High fitness levels, frequent sauna bathing and risk of pneumonia in a cohort study: Are there potential implications for COVID‐19?
Setor K Kunutsor, Jari A Laukkanen
European Journal of Clinical Investigation, doi:10.1111/eci.13490
Pneumonia infection is the result of a complex inflammatory process where the lower respiratory tract suffers the invasion of an infective microorganism (viruses or bacteria). Major risk factors that predispose to pneumonia include smoking, obesity, underweight, excessive alcohol consumption and comorbid conditions such as asthma,
CONFLICT OF INTEREST No potential conflict of interest was reported by the authors.
AUTHOR CONTRIBUTIONS SKK contributed to study design, data analysis and interpretation, drafting manuscript, and revising manuscript content and approving the final version of the manuscript; JAL contributed to study design and conduct, responsibility for the patients and data collection, and revising manuscript content and approving the final version of the manuscript.
SUPPORTING INFORMATION Additional supporting information may be found online in the Supporting Information section. How to cite this article: Kunutsor SK, Laukkanen JA. High fitness levels, frequent sauna bathing and risk of pneumonia in a cohort study: Are there potential implications for COVID-19?. Eur J Clin Invest. 2021;51:e13490. https://doi.org/10.1111/eci.13490
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'abstract': '<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>There '
'is an ongoing debate on a potential protective role of habitual physical activity and passive '
'heat therapy on the risk of COVID‐19, a respiratory infectious disease that can manifest as '
'severe pneumonia. To explore these putative roles, we evaluated the independent and joint '
'associations of cardiorespiratory fitness (CRF) and frequency of sauna bathing (FSB) with '
'pneumonia risk in a prospective cohort study of 2275 men aged 42‐61\xa0years at '
'recruitment.</jats:p></jats:sec><jats:sec><jats:title>Material and '
'Methods</jats:title><jats:p>Objectively measured CRF and self‐reported sauna bathing habits '
'were assessed at baseline. CRF was categorized as low and high (median cut‐offs) and FSB as '
'low and high (defined as ≤1 and 2‐7\xa0sessions/wk, respectively). Multivariable‐adjusted '
'hazard ratios (HRs) with confidence intervals (CIs) were calculated for incident '
'pneumonia.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>During a '
'median follow‐up of 26.6\xa0years, 529 cases of pneumonia occurred. Comparing high vs low '
'CRF, the multivariable‐adjusted HR (95% CIs) for pneumonia was 0.75 (0.61‐0.91). Comparing '
'high vs low FSB, the corresponding HR was 0.81 (0.68‐0.97). Compared to men with low CRF '
'& low FSB, the multivariable‐adjusted HRs of pneumonia for the following groups: high CRF '
'& low FSB; low CRF & high FSB; and high CRF & high FSB were 0.88 (0.65‐1.20), '
'0.89 (0.71‐1.13), and 0.62 (0.48‐0.80) '
'respectively.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>In a '
'general male Caucasian population, a combination of high fitness levels and frequent sauna '
'baths is associated with a substantially lowered future pneumonia risk compared with each '
'modality alone. The implications of these findings in altering COVID‐19 disease or its '
'severity deserve study.</jats:p></jats:sec>',
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